Name: flame test metal color clues
Uploaded: 2020-03-26T07:22:25.000Z
Duration: 2 min 47 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Chemistry and Physics

IPC.7

IPC.7.E

Metal Flame Emission

화염 테스트는 샘플을 화염에 적용하는 분석 기술이며, 특성 방출 스펙트럼을 사용하여 다양한 원소를 식별합니다. 이 기술을 사용하여 금속 종을 식별하는 경우 금속 화염 방출 테스트라고 합니다. 뜨거운 불꽃을 통해 일부 금속에 충분한 에너지를 가하면 특유의 파장이나 색상으로 빛을 방출합니다. 불꽃놀이를 보면 이런 현상을 분명히 볼 수 있습니다.
다른 금속은 다른 색상을 방출합니다. 따라서 방출된 빛의 색상을 사용하여 존재하는 금속을 결정할 수 있습니다. 그러나 기술에 대해 더 자세히 알아보기 전에 한 걸음 물러서겠습니다. 원자는 전자에 대해 여러 에너지 준위를 가지고 있으며 이는 각 원소마다 다릅니다.
전자가 가능한 가장 낮은 에너지 수준에 있을 때 바닥 상태라고 합니다. 원자가 에너지를 흡수하면 여기가 되고 원자 내의 전자는 바닥 상태에서 더 높은 에너지 수준으로 이동합니다. 전자가 다시 이완되어 더 낮은 상태 또는 바닥 상태로 내려갈 때 얻은 초과 에너지는 방출된 빛의 형태로 방출됩니다.
방출된 빛의 파장은 전자가 여기된 에너지 수준과 다시 이완되는 수준에 따라 달라집니다. 이 방출된 파장 또는 빛의 색은 존재하는 원자에 따라 다르며 금속 화염 방출 테스트에서 금속 샘플을 식별하는 데 사용됩니다.
금속 화염 방출 시험에서는 뜨거운 화염에 금속 샘플을 적용하고 방출되는 빛의 색상을 관찰합니다. 예를 들어, 바륨은 불꽃에서 황록색을 방출하는 반면 구리는 청록색을, 칼륨은 분홍빛을 띤 자주색을 방출합니다.
이제 샘플은 실제로 금속, 금속 이온, 금속 산화물, 금속 수산화물 및 금속염으로 구성됩니다. 그리고 원자와 분자는 에너지를 다르게 흡수하고 방출하기 때문에 방출된 빛은 실제로 방출 스펙트럼을 형성하는 다양한 파장과 강도를 포함합니다.
분광 광도계는 방출되는 빛의 파장 범위를 측정하는 데 사용됩니다. 
이 실습에서는 금속 화염 방출 테스트를 사용하여 다양한 금속을 식별한 다음 분광 광도계를 사용하여 방출 및 흡수된 빛을 분석합니다.

금속 화염 방출

<h4>금속 화염 방출</h4>
화염 테스트는 샘플을 화염 속에 넣고 특징적인 화염 색상을 사용하여 물질을 식별하는 분석 기술입니다. 각 요소는 화염에 배치될 때 특징적인 광 방출을 가지므로 각 요소가 고유한 색상을 생성합니다. 이 현상은 불꽃 놀이에 사용되며, 불꽃 놀이의 색은 금속의 특정 특성에 해당합니다. 연소 샘플에서 유색 광이 방출되는 것은 화염의 여기로 인해 금속 성분이 에너지를 흡수하고 결과적으로 빛을 방출하는 직접적인 결과입니다.
<h4>전자 흥분</h4>
원자 또는 분자 종이 에너지를 흡수할 때 에너지는 네 가지 다른 방식으로 사용됩니다. 첫째, 에너지가 번역에 사용되어 분자가 더 빨리 움직이게 됩니다. 둘째, 에너지는 진동에 사용되어 종 사이의 거리가 급격히 변합니다. 셋째, 에너지는 회전을 일으켜 분자의 결합 주위로 원자의 회전을 유도합니다. 마지막으로, 흡수된 에너지는 전자 여기를 일으켜 전자가 가장 안정적인 상태 또는 바닥 상태에서 더 높은 에너지 수준으로 이동하게 합니다.
보어(Bohr)의 수소 모델에 따르면, 원자 속의 전자는 핵 주위의 개별 껍질 또는 궤도에 해당하는 개별 상태로 존재합니다. 가장 낮은 에너지 상태를 바닥 상태라고 하며 n = 1로 표기합니다. 여기 에너지 상태는 더 높은 에너지를 가지며 n = 2, 3, 4 등의 표기법으로 표시됩니다.
전자가 더 높은 에너지 상태로 이동하려면 바닥 상태와 더 높은 에너지 상태의 차이와 동일한 양의 에너지를 흡수해야 합니다. 예를 들어, 전자가 바닥 상태와 n=3 에너지 준위의 차이와 동일한 양의 에너지를 흡수하면 전자는 n=3 에너지 준위로 이동합니다. 전자는 자발적으로 이완되어 바닥 상태 또는 다른 낮은 에너지 수준으로 다시 내려갈 수 있습니다. 이 경우 광자가 방출되어 흡수된 에너지가 방출됩니다.
방출된 에너지는 빛의 형태로 방출됩니다. 방출된 빛은 원자의 에너지 준위와 상관관계가 있는 특징적인 에너지를 가지고 있으므로 파장이 있습니다. 인간이 눈으로 볼 수 있는 빛인 가시광선은 전자기 스펙트럼에서 약 400nm에서 700nm 사이입니다.
원자 흡수와 방출은 선이라고 하는 불연속 파장입니다. 이러한 선은 바코드와 같은 요소의 고유한 특성이며 요소를 식별하는 데 사용할 수 있습니다.
<h4>금속 화염 방출 테스트</h4>
금속 화염 방출 테스트에서는 금속 샘플을 화염에 넣습니다. 불꽃은 전자를 더 높은 에너지 수준으로 여기시키는 에너지를 제공합니다. 전자가 다시 바닥 상태로 이완됨에 따라 샘플에 있는 원자의 에너지 준위에 상대적인 특정 에너지로 빛이 방출됩니다. 서로 다른 원자는 서로 다른 에너지 준위를 갖기 때문에 샘플에서 흡수 및 방출되는 에너지와 그에 따른 파장은 샘플에 따라 다릅니다.
금속은 가시 범위에서 특징적인 원자 방출 파장을 가지고 있으며 이는 육안 검사로 쉽게 확인할 수 있습니다. 예를 들어, 리튬은 빨간색, 나트륨은 노란색, 칼륨은 분홍색-보라색, 바륨은 황록색을 방출합니다.
원자 방출은 별개의 파장 또는 선이지만 대부분의 금속 샘플에는 금속뿐만 아니라 다양한 금속 이온, 산화물 및 염이 포함되어 있습니다. 각 원자는 특징적인 파장의 빛을 흡수하고 방출하기 때문에 화염 테스트에서 흡수 및 방출된 빛에는 다양한 파장이 포함됩니다. 따라서, 원자 흡수 및 방출 스펙트럼은 분광 광도계를 사용하여 샘플에 대해 측정 할 수 있습니다.
스펙트럼의 파장과 모양은 각 물질마다 고유합니다. 예를 들어, 스펙트럼에 있는 특징의 상대적 강도는 종의 농도에 따라 달라집니다. 절대 강도는 샘플에서 분광 광도계까지의 거리에 따라 달라집니다.
<h4>참조</h4>
<ol>
	<li style="font-size:17px">Kotz, J.C., Treichel Jr, P.M., Townsend, J.R. (2012). 화학 및 화학 반응성. 캘리포니아 벨몬트 : Brooks / Cole, Cengage Learning.</li>
	<li style="font-size:17px">Silderberg, M.S. (2009). 화학: 물질과 변화의 분자적 성질. 매사추세츠주 보스턴: 맥그로 힐.</li>
	<li style="font-size:17px">Harris, D.C. (2015). 정량적 화학 분석. 뉴욕, 뉴욕 : WH 프리먼 앤 컴퍼니.</li>
</ol>

금속 화염 방출
화염 테스트는 샘플을 화염에 넣고 특징적인 화염 색상을 사용하여 식별하는 분석 기술입니다.

Education

교육

JoVE Lab Manual

Chemistry

화학

flame test metal color clues

Flame testing uses a metal sample and a flame to identify a substance by its color. Each element gives off a characteristic light emission in the flame, so the color can help distinguish one element from another. This same idea appears in fireworks, where different metal components create different colors.

The color comes from energy absorbed by the metallic component. When a species absorbs energy, that energy can go into translation, vibration, rotation, or electron excitement. Electron excitement is the key step in flame emission because it moves electrons from the ground state, the lowest energy state, to a higher energy level.

In the Bohr model of hydrogen, these energy states are separate, or discrete. The ground state is written as n = 1, and higher states are written as n = 2, 3, 4, and so on. An electron moves up only if it absorbs the exact energy difference between its current level and the higher one.

The electron can then relax back to the ground state or another lower level. When that happens, a photon is released as light. The emitted light has a specific energy and wavelength, and visible light ranges from about 400 nm to 700 nm. These atomic absorption and emission wavelengths are discrete lines, and they act like a barcode for identifying an element.

In a metal flame emission test, the flame supplies the energy that excites the electrons. As the electrons fall back down, the sample gives off light with a wavelength tied to its atomic energy levels. Because different atoms have different energy levels, the emitted wavelength is specific to the sample.

Many metals show visible colors that are easy to spot by eye. Lithium gives a red color, sodium gives yellow, potassium gives pink-purple, and barium gives yellow-green. Real samples often contain metal ions, oxides, and salts as well as the metal itself, so the light from the flame test can include a range of wavelengths.

That range can also be measured with a spectrophotometer as atomic absorption and emission spectra. The shapes and wavelengths of the spectra are unique for each substance. The relative intensity of spectral features depends on concentration, while the absolute intensity depends on the distance from the sample to the spectrophotometer.

Flame Test Metal Color Clues

lab techniques

Measuring with Accuracy in the Lab

Measuring with accuracy in the lab starts with careful records, the right tools, and correct reading of data. Scientists use lab notebooks to record how an experiment was done. These notes include the amounts of materials used and each step of the procedure. Without that record, an experiment cannot be repeated in the same way. Balances and glassware are used to measure solids and liquids for experiments. The precision of a measurement depends on the equipment used. Digital balances show the...

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Graphs, Curve Fit, and Standard Deviation

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stoichiometry, product yield, and limiting reactants

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Balancing Equations and Reactant Limits

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Oxidation States in Redox Reactions

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Gas Laws Behind the Ideal Gas Equation

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acid and base concentrations

Acids, Bases, and pH in Titration

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buffers

Buffer pH and the Common Ion Effect

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Reaction Heat, Hess’s Law, and Calorimetry

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solubility

Solubility in Water and Other Solvents

Solubility describes how much of a solute can dissolve in a specific solvent. It is usually reported as solute mass per solvent volume or as solute mass per solvent mass. For example, sodium chloride has a solubility of 36 g per 100 mL of water at room temperature. If solubility is given by solvent mass, that mass must be converted to volume for later calculations. Temperature changes solubility. Sodium carbonate dissolves at about 7 g per 100 mL of water at 0 °C, 22 g per 100 mL at room...

metal flame emission

Flame testing uses a metal sample and a flame to identify a substance by its color. Each element gives off a characteristic light emission in the flame, so the color can help distinguish one element from another. This same idea appears in fireworks, where different metal components create different colors. The color comes from energy absorbed by the metallic component. When a species absorbs energy, that energy can go into translation, vibration, rotation, or electron excitement. Electron...

balmer series

Hydrogen Emission Lines

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beer's law

Absorbance Spectra and Beer-Lambert Analysis

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concentration dependence

Reaction Order and Rate Constants

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Reaction Rate, Arrhenius, and Catalysts

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Battery Power from Redox Reactions

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Electroplating with Electrolytic Cells

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Recording a Reproducible Lab Experiment

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Organic Lab Glassware and Safe Handling

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melting points

How Impurities Change Melting Points

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boiling points

Boiling Point and Vapor Pressure

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Purifying Crystals by Solubility

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extraction

Separating Mixtures with Solvent Extraction

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simple distillation

Separating Liquids by Boiling Point

Separating liquids by boiling point is the goal of distillation. A miscible mixture contains liquids that mix evenly, and it can be heated so that the more volatile liquid evaporates first. Volatility is a liquid’s tendency to vaporize, and boiling begins when bubbles form in the liquid phase. In a closed container, liquid and vapor can reach equilibrium, which means the rate of vaporization equals the rate of condensation. The pressure from the vapor above the liquid is called vapor pressure.

steam distillation

Steam Distillation and Low-Boiling Separation

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thin-layer chromatography

TLC Separation by Polarity

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column chromatography

Separating Mixtures by Polarity

Column chromatography separates compounds in an organic chemistry lab by using differences in physical properties. It is especially useful for microscale separations when less than 10 grams of material is available for analysis. The method can separate a mixture based on solubility, polarity, hydrophobicity, size, and charge. Any chromatography system has three main parts: the stationary phase, the mobile phase, and the sample mixture. In column chromatography, the stationary phase is usually...

hydrolysis of an ester

Soap Formation from Triglycerides

Triglycerides are lipids made of a glycerol backbone linked to three fatty acids. They are common in vegetable oils and animal fats. Plant lipids are the basis of vegetable oils, while animal lipids are used as lard or general sources of fats. A fatty acid has a long carbon chain, usually between 12 and 20 carbons, with a weak organic acid at one end. Some fatty acids contain double bonds. These are unsaturated fats. The double bond usually gives the chain a bent, cis shape. As a result,...

synthesis of luminol

Luminol Chemiluminescence in Forensics

Luminol chemiluminescence shows how a chemical reaction can produce light and help with blood detection. Chemical reactions may be endothermic or exothermic, depending on whether they absorb or release heat as reactants become products. The enthalpy of a reaction is the energy difference between reactants and products, or ΔH. A positive ΔH means the reaction is endothermic. A negative ΔH means it is exothermic. Many reactions do not happen in a single step. They can pass through intermediates...

esterification

Ester Formation and Everyday Fragrances

Esters are organic compounds with a carbonyl group attached to an oxygen that connects to another alkyl or aryl group. Their general formula is RCOOR'. They are often made by reacting a carboxylic acid with an alcohol in an esterification reaction. In this process, the hydroxyl group of the acid is replaced by an alkyl or aryl group. Many simple esters have familiar fruit and flower smells because their structures are small and less complex. Formic acid and methanol can combine to form methyl...

identification of unknown aldehydes and ketones

identification-of-unknown-aldehydes-and-ketones

Carbonyl Tests for Aldehydes and Ketones

Aldehydes and ketones are carbonyl compounds, which means they contain a C=O functional group. A ketone has two alkyl or aryl groups attached to the carbonyl carbon. Acetone is the simplest ketone, with two methyl groups. An aldehyde is similar, but it has at least one hydrogen attached to the carbonyl carbon. Formaldehyde is the simplest aldehyde, and acetaldehyde has one hydrogen and one methyl group. The carbonyl carbon in both aldehydes and ketones is electrophilic because the oxygen atom...

uv-vis spectroscopy of dyes

How Dyes Absorb Visible Light

Dyes absorb visible light because their molecular structure lets them interact with specific wavelengths. When light hits a substance, some light is absorbed and the rest is reflected or transmitted. The color we see depends on the wavelength that is reflected. A blue substance reflects blue light, around 430 to 480 nm, and absorbs the complementary orange region, around 590 to 630 nm. Compounds that do not absorb in the visible range appear colorless to the human eye. Light also has energy and...

identifying alcohols

Alcohol Tests for Primary, Secondary, and Tertiary

Alcohol tests can help sort alcohols by structure and reactivity. Alcohols are organic molecules with a hydroxyl group attached to an alkyl or aryl group, written as ROH. If the carbon with the hydroxyl group has one R group, the alcohol is primary. If it has two R groups, it is secondary. If it has three R groups, it is tertiary. Alcohols can also be aromatic when they contain a benzene ring. Phenol is the simplest aromatic alcohol. To identify an alcohol, chemists can use its chemical...

chemistry

화학 실험실에서 꼭 필요한 기본 커리큘럼 중심 비디오입니다.

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Learn how flame testing identifies metals by color, why electrons emit light in the flame, and how spectra reveal each element's unique wavelengths.

Flame Test Metal Color Clues | JoVE K12

Pennsylvania State Academic Standards

9-12

Earth and Space Science

Space Systems

3.3.9-12.B

Louisiana Student Standards for Science

Earth Science

Earth’s Place In The Universe

HS-ESS1-2

motion-and-stability-forces-and-interactions

Motion And Stability: Forces And Interactions

HS-PS2-6

IPC.7.D

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

waves-and-their-applications-in-technologies-for-information-transfer

Waves and Their Applications in Technologies for Information Transfer

C-PS4-5

2분 길이의 강사용 가이드를 통해 금속 화염 방출 수업을 준비하세요. JoVE Lab Manual의 Chemistry 실험을 위한 핵심 준비 단계를 다룹니다.

Chemistry의 금속 화염 방출 강사용 준비 - 2.6K+ 조회수 | JoVE Lab Manual

7분 길이의 학생 프로토콜 영상을 통해 금속 화염 방출 절차를 단계별로 따라 해보세요. JoVE Lab Manual의 Chemistry 컬렉션의 일부입니다.

Chemistry의 금속 화염 방출 학생 프로토콜 - 6.9K+ 조회수 | JoVE Lab Manual

The Atomic Theory of Matter

The earliest recorded discussion of the basic structure of matter comes from ancient Greek philosophers. Leucippus and Democritus argued that all matter ...

Subatomic Particles

Dalton was only partially correct about the particles that make up matter. All matter is composed of atoms, and atoms are composed of three smaller ...

Elements: Chemical Symbols and Isotopes

A chemical symbol is an abbreviation used to indicate an element or an atom of an element. For example, the symbol for mercury is Hg. The same symbol is ...

Ions and Ionic Charges

In ordinary chemical reactions, the nucleus &mdash; which contains the protons and neutrons of each atom and thus identifies the element &mdash; remains ...

The Periodic Table

As early chemists discovered more elements, they realized that various elements could be grouped by their similar chemical behaviors. One such grouping ...

Atomic Mass

Atoms &mdash; and the protons, neutrons, and electrons that compose them &mdash; are extremely small. For example, a carbon atom weighs less than 2 ...

Molar Mass

The identity of a substance is defined not only by the types of atoms or ions it contains but by the quantity of each type of atom or ion. For example, ...

Periodic Classification of the Elements

The periodic table arranges atoms based on increasing atomic number so that elements with the same chemical properties recur periodically. When their ...

Types of Chemical Bonds

Chemical bonding theories were pioneered by American chemist Gilbert&#xA0;N. Lewis. He developed a model called the Lewis model to explain the type and ...

Ionic Bonding and Electron Transfer

Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence ...

The Born-Haber Cycle

Lattice Energy&#xA0;

An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a ...

trends-in-lattice-energy-ion-size-and-charge

Trends in Lattice Energy: Ion Size and Charge

An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure ...

Covalent Bonding and Lewis Structures

Compared to ionic bonds, which results from the transfer of electrons between metallic and nonmetallic atoms, covalent bonds result from the mutual ...

Electronegativity

Whether a bond is nonpolar or polar covalent is determined by a property of the bonding atoms called electronegativity.&#xA0;

Electronegativity values of ...

bond-polarity-dipole-moment-and-percent-ionic-character

Bond Polarity, Dipole Moment, and Percent Ionic Character

Bond Polarity

The absolute value of the difference in electronegativity (&Delta;EN) of two bonded atoms provides a rough measure of the polarity to be ...

lewis-structures-of-molecular-compounds-and-polyatomic-ions

Lewis Structures of Molecular Compounds and Polyatomic Ions

To draw Lewis structures for complicated molecules and molecular ions, it is helpful to follow a step-by-step procedure as outlined:


	Determine the ...

Bond Energies and Bond Lengths

Stable molecules exist because covalent bonds hold the atoms together. The strength of a covalent bond is measured by the energy required to break it, ...

Bonding in Metals

Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Dr&#xFC;de called the ...

Model basic atomic structure and relate an element's atomic structure to its bonding, reactivity, and placement on the Periodic Table.

IPC.7.A

physical-and-chemical-properties-of-matter

Physical and Chemical Properties of Matter

The characteristics that enable us to distinguish one substance from another are called properties.

Physical Properties of Matter

A physical property is ...

atomic-radii-and-effective-nuclear-charge

Atomic Radii and Effective Nuclear Charge

The elements in groups of the periodic table exhibit similar chemical behavior. This similarity occurs because the members of a group have the same number ...

Ionic Radii

Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it ...

Ionization Energy

The amount of energy required to remove the most loosely bound electron from a gaseous atom in its ground state is called its first ionization energy ...

Electron Affinity

The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion).



This process can be either ...

Alkali Metals

Group 1 elements are soft and shiny metallic solids. They are malleable, ductile, and good conductors of heat and electricity. The melting points of the ...

Halogens

Group 17 elements, known as halogens, are nonmetals. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine a solid. ...

Noble Gases


The elements in group 18 are noble gases (helium, neon, argon, krypton, xenon, and radon). They earned the name &ldquo;noble&rdquo; because they were ...

Use patterns within the Periodic Table to predict the relative physical and chemical properties of elements.

IPC.7.B

Science concepts. The student knows that relationships exist between the structure and properties of matter. The student is expected to:

Flame Test Metal Color Clues

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